Introduction
The HAL320 is a differential Hall switch produced in CMOS technology. The sensor includes 2 temperature compensated Hall plates (2.25 mm apart) with active off set compensation, a differential amplifier with a Schmitt trigger, and an open-drain output transistor (see Fig. 2–1).
The HAL320 is a differential sensor which responds to spatial differences of the magnetic field. The Hall voltages at the two Hall plates, S1 and S2, are amplified with a differential amplifier. The differential signal is compared with the actual switching level of the internal Schmitt trigger. Accordingly, the output transistor is switched on or off.

FEATUREs:
– distance between Hall plates: 2.25 mm
– operates from 4.5 V to 24 V supply voltage
– switching offset compensation at 62 kHz
– overvoltage protection
– reverse-voltage protection at VDD-pin
– short-circuit protected open-drain output by thermal shutdown
– operates with magnetic fields from DC to 10 kHz
– output turns low with magnetic south pole on branded side of package and with a higher magnetic flux density in sensitive area S1 as in S2
– on-chip temperature compensation circuitry minimizes shifts of the magnetic parameters over temperature and supply voltage range
– the decrease of magnetic flux density caused by rising temperature in the sensor system is compensated by a built-in negative temperature coefficient of hysteresis
– EMC corresponding to ISO 7637